The number of countries executing rose, from 22 in 2014 to 25 in 2015. At least six countries who had not put anyone to death in 2014 did so in 2015, including Chad where executions were carried out for the first time in more than a decade.

Most of Iran's executions were for drug-related crimes.

Iran is also one of the world’s last executioners of juvenile offenders, in flagrant breach of international law. The country put to death at least four people who were under 18 at the time of the crime for which they were convicted in 2015.

...In Saudi Arabia, executions rose by 76% on 2014’s figures, as at least 158 people were put to death last year. Most were beheaded, but authorities also used firing squads and sometimes displayed executed bodies in public.

AI calls the increase "alarming" and says the slaughter must stop.